1. Technical Field
The present invention relates to a relative angle sensing device and a production method of a relative angle sensing device.
2. Related Art
In recent years, there has been suggested a technique for improving production yield of a torque sensing device (relative angle sensing device) used for an electric power steering apparatus.
For example, a torque sensing device described in Japanese Patent Application Laid Open Publication No. 2009-168727 has a following configuration. That is, the torque sensing device includes: a first shaft and a second shaft that are coaxially connected to each other through a connecting shaft; a permanent magnet that is fixed to the first shaft or one end of the connecting shaft; a pair of sensor yokes that is fixed to the second shaft or the other end of the connecting shaft and that forms a magnetic circuit together with the permanent magnet; and a pair of magnetism collection yokes that forms the magnetic circuit together with the permanent magnet and the pair of sensor yokes; and a magnetic flux sensing device that senses a magnetic flux induced by the sensor yokes and the magnetism collection yokes, and the torque sensing device senses the torque applied any one of the first shaft and the second shaft on the basis of output of the magnetic flux sensing device. The pair of sensor yokes is obtained by punching a pair of band-shaped sensor yoke components from a flat sheet component, and curving the pair of band-shaped sensor yoke components so as to be respectively formed into a ring.